Biopowered - vegetable oil and biodiesel forum
Biodiesel => Chemistry and process => Topic started by: Manfred on March 01, 2014, 10:50:11 AM
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After a perfect 10/90 on a 90 ltr mix I did a pre wash then 3x 10 ltr pump washes. Result the water was sparkling clear. So being the sort who prods wet paint to see if it's dry I did one more wash. Bum soapy water with a white interface. No worries I put 2 ltr of Glycol and mixed, looked ok so added 10 ltr of warm water. Instant mayonnaise so I added acid until split. Peed me off as I didn't want to do this because of interfering with the acid soap test. So now I'm back to square one. Has anyone else experienced this ?
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Recently had my first emulsion when doing a 7% prewash with the glycerin. I magined to split it with acid but it wasn't a very convincing split, separating to two phases ... water and what I assume was a dark brown bio glycerin mix which showed only tentative signs of dropping the glycerin.
I think if I'd been more patient, it would have split but as it's log burner season I made it into blogs (or has that word already been coined)
As for subsequent washes, I usually do a titrated acid wash which has never resulted in an emulsion, save the first signs of one created mechanically by Frankenpump. (just running another batch at the moment and I think the combination of Frankenpump and convoluted pipework are showing rather good benefits ... if my thoughts are correct, I'll put up another thread).
Don't worry about making the bio acidic. To the best of my limited knowledge, if you wash and dry thouroughly after an acid wash (or splitting an emulsion), it's not possible for any of the acid you added to remain.
The only realistic action you have is to carry on washing and test it. Posting your results would be of great interest.
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We'll I'm on the second 10 ltr pump wash after my mayo disaster and all seems ok. I just can't figure why it happened after a perfect clear pump wash. All wash water is from the hot tap so temp is 40 Deg. in the processor.
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Ps. With the acid I got the brown scum appear, same as you got in a earlier post.
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Ps. With the acid I got the brown scum appear, same as you got in a earlier post.
I wish my chemistry was better, but I think that's sodium sulfate (if you used sulfuric acid). Keep washing and dry well and I'm sure it will be OK.
These little hiccups happen from time to time. Often due to the brewer becoming blasé about things (well, usually is in my case), but that's what makes brewing fun!
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It's something in the air - I blame the polar vortex.....
No only kidding. I do have a troublesome batch just finishing washing now as well. It was only around half my normal batch size as emptying the oil storage tank before dumping a load of palm in there to melt. All went well up to first water wash after the acid which went very wrong and the next after it wasn't much better.
In the end I did another acid wash and left that to settle overnight. All seems to be OK now thankfully and I should be drying it overnight tonight.
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Nice to know we're in good company!
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I've never had a water wash go wrong in 8 yrs.
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Re: Pump wash gone wrong.
« Reply #7 on: Today at 01:35:26 pm »
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I've never had a water wash go wrong in 8 yrs.
I didn't know I was that good. I only been doing it 8 months :)
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Ask the old bugger to qualify his statement a little!
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Been thinking about this. Even though I had a instant 10/90 if I had any mono and diglycerides present, after a clear wash taking out any buffer with it would any more washes cause these to create the emulsion I got ?
After two more 10 ltr washes Ph paper indicated neutral water so I tritated for soap and got 15 ppm. Going for a dry then settle to see what falls out.
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Ask the old bugger to qualify his statement a little!
Ok, it's got an NVQ.
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Doesn't that stand for Not Very Qualified Jim? Much like HND stands for Have No Degree
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).
Don't worry about making the bio acidic. To the best of my limited knowledge, if you wash and dry thouroughly after an acid wash (or splitting an emulsion), it's not possible for any of the acid you added to remain.
The first and last time I used vinegar as part of the washing process all went fantastically, however Paul AKA Carrington fuels tested for acidity and it was acidic, and with that sample it did not make any difference with subsequent washing it just stayed acidic. Paul also tried other methods of reducing the acidity without success.
As I really had no intention to use that process anymore I didn't follow up with further testing and just mixed that batch with another which was just washed. I am back to simply settling and centrifuging, a 50/50 test is always clear afterwards.
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I've never had a water wash go wrong in 8 yrs.
I fought U settled and didn't wash.
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That is why he has never had a water wash go wrong in 8 years - if you dont use a process then it cant go wrong.
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).
Don't worry about making the bio acidic. To the best of my limited knowledge, if you wash and dry thouroughly after an acid wash (or splitting an emulsion), it's not possible for any of the acid you added to remain.
The first and last time I used vinegar as part of the washing process all went fantastically, however Paul AKA Carrington fuels tested for acidity and it was acidic, and with that sample it did not make any difference with subsequent washing it just stayed acidic. Paul also tried other methods of reducing the acidity without success.
As I really had no intention to use that process anymore I didn't follow up with further testing and just mixed that batch with another which was just washed. I am back to simply settling and centrifuging, a 50/50 test is always clear afterwards.
Interesting, how did Paul test the acidity of biodiesel?
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I've never had a water wash go wrong in 8 yrs.
I fought U settled and didn't wash.
Very true but why let that stand in the way of a good result.
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I've never had a water wash go wrong in 8 yrs.
I fought U settled and didn't wash.
Very true but why let that stand in the way of a good result.
I've never once been bitten when wrestling crocodiles.
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I've never had a water wash go wrong in 8 yrs.
I fought U settled and didn't wash.
Very true but why let that stand in the way of a good result.
I've never once been bitten when wrestling crocodiles.
You should stop that, it's very dangerous, one day you're gonna get bitten.
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I've never had a water wash go wrong in 8 yrs.
I fought U settled and didn't wash.
Very true but why let that stand in the way of a good result.
I've never once been bitten when wrestling crocodiles.
In all fairness I'd be pretty bitey if I was a crocodile and someone tried to water wash their bio with me.
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).
Don't worry about making the bio acidic. To the best of my limited knowledge, if you wash and dry thouroughly after an acid wash (or splitting an emulsion), it's not possible for any of the acid you added to remain.
The first and last time I used vinegar as part of the washing process all went fantastically, however Paul AKA Carrington fuels tested for acidity and it was acidic, and with that sample it did not make any difference with subsequent washing it just stayed acidic. Paul also tried other methods of reducing the acidity without success.
As I really had no intention to use that process anymore I didn't follow up with further testing and just mixed that batch with another which was just washed. I am back to simply settling and centrifuging, a 50/50 test is always clear afterwards.
Interesting, how did Paul test the acidity of biodiesel?
Sorry to be honest it was that long ago the tech info has been overwritten in my brain. As he had spent a good couple of hours trying this that and the other trying to lower the acidity I had already decided it was too risky to have acidic Bio and put the whole process out of my mind.
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My info came from a mate who's a PhD in chemistry. Bio's not his branch of chemistry, but he seems to know what he's talking about. Just on logic, what my mate says seems to make sense to my simplistic brain, in the the acid we add ie sulfuric is a water based substance.
Assuming the bio holds water during washing (noticeable by the colour and clarity), then it can hold some of the sulfuric acid. Further washing will dilute the acid and once the bio is completely dried it can no longer exist.
This issue has always confused me. I thought I had it straight having had the discussion with my mate, but now from what you report Paul has stated, I'm back in the realms of confusion.
I'll try dropping Paul a mail and see what he says.
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I just did a ph paper test on my dried bio. 50/50 with water shuck up read 7. I then added 1 ml of 30% sulphuric to a new sample! shuck it up then added water as a 50/50 test. I got a instant 1. So maybe we can test the water as it seems to transfer over from the Bio.
I will leave overnight to settle then dry the sample tomorrow to see if it goes back to neutral. Will be interesting.
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When I first started acid washing I tested the wash water with litmus paper. It was always neutralish after a couple of washes.
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I just did a ph paper test on my dried bio. 50/50 with water shuck up read 7. I then added 1 ml of 30% sulphuric to a new sample! shuck it up then added water as a 50/50 test. I got a instant 1. So maybe we can test the water as it seems to transfer over from the Bio.
I will leave overnight to settle then dry the sample tomorrow to see if it goes back to neutral. Will be interesting.
I would be think that hydrogen ions (acidity) would transfer to the water easily. Im wondering what the scenario could be where they would not?
This is relevant to both testing the acidity of the bio (as above) and washing the acid from the bio (as in Steve's case) - so i wonder what was happening with Steve's bio?
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I just did a ph paper test on my dried bio. 50/50 with water shuck up read 7. I then added 1 ml of 30% sulphuric to a new sample! shuck it up then added water as a 50/50 test. I got a instant 1. So maybe we can test the water as it seems to transfer over from the Bio.
I will leave overnight to settle then dry the sample tomorrow to see if it goes back to neutral. Will be interesting.
I would be think that hydrogen ions (acidity) would transfer to the water easily. Im wondering what the scenario could be where they would not?
This is relevant to both testing the acidity of the bio (as above) and washing the acid from the bio (as in Steve's case) - so i wonder what was happening with Steve's bio?
Paul could not work out why further washes were not reducing it in this instance, so long as people are happy that they are getting near on Ph neutral Bio that is all that matters.
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Really interesting results on the Ph testing. After leaving the sample 24 hours to settle out, I tested the bio and got a neutral reading, the water however still read acidic. So the water must have fell out of suspension. Heating the bio to drive off any moisture read the same, neutral. So bio can't hold an acidic reading unless water is present.
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Really interesting results on the Ph testing. After leaving the sample 24 hours to settle out, I tested the bio and got a neutral reading, the water however still read acidic. So the water must have fell out of suspension. Heating the bio to drive off any moisture read the same, neutral. So bio can't hold an acidic reading unless water is present.
That what I thought, but Paul, although self taught, is quite a whiz at bio chemistry. I've sent him an email but as yet haven't received a reply.
I'm reserving judgment until I hear Paul's side of things.
What ever the outcome, I don't think testing bio using litmus paper is viable ... the wash water yes, but not bio. I'm guessing Paul may have used some form of titration.
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I agree it's the water to be tested or preferably a titration if possible.
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I have been using the titrated acid wash process since August/September 2012 when Paul originally asked myself and KH to trial it.
I have used no other process in all that time, all my fuel for both the heating and road vehicles has been made that way.
After the acid wash, I do one water wash for the heating fuel and two for the road fuel.
I have not seen any problems with either the boiler fuel pump or the vehicle pumps so I think it is safe to assume that the finished dry fuel is pretty safe and free from any acidity.
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When you do a titrated acid wash you measure how Much acid to add to stabilise the addition of water. When it turns yellow you know that it's on the acidic side of the table so safe to proceed. When all water washes are done if you do a test and it turns yellow instantly you know that you have no soaps present. So it's good to use, but how far is it into the acidic side as green is a neutral reading. Or am I understanding this wrong.
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I've heard back from Paul as follows ...
Hi Julian
Sorry about the delay things are really up in the air at the mo.
In answer to your question bio cannot become acidic if it is completely reacted and well dried.
By doing a 50/50 water test then testing the water is by far the most straight forward and easiest way to test for acidity. If you can get your hands on a reagent called BTB in ethanol this is a good indicator for pH as the neutral is quite a small window. A quick test I just draw some in a pipette then down into settled water no mess.
With regards to Steve's samples I tested ,I remember doing the tests and the results but can't remember any definite conclusion so not really sure.
One thing to remember though is strong acid in too high a dosage can make the methanol disassociate from the fatty acid (not a problem for titrated acid wash or going at it slowly but does mean that in theory you could turn the whole batch to Ffa then wash the methanol out .
Will try and pop into biopowerd soon just got lots going on.
Hope this helps a bit.
Cheers,
Paul
So it looks like Paul agrees with my PhD mate, that if completely reacted, washed and dried, bio cannot be acidic.
He then sent what looks to be a useful snippet, but it leaves me wondering why do a titration titration to arrive at the volume of acid? I guess doing a titration and making a comparison will help explain things.
Hi Julian
No problem with cut and paste my reply to the forum.
Also a quick calc that may be helpful for people using conc sulphuric acid is to X the base amount used of sodium by 0.12 for amount of acid required .
Example
2L ASM /5=400g base X ,0.12 =48ml conc sulphuric acid .
This can then be adjusted for any concentration of sulphuric acid.
Be back soon
Cheers
Paul
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When you do a titrated acid wash you measure how Much acid to add to stabilise the addition of water. When it turns yellow you know that it's on the acidic side of the table so safe to proceed. When all water washes are done if you do a test and it turns yellow instantly you know that you have no soaps present. So it's good to use, but how far is it into the acidic side as green is a neutral reading. Or am I understanding this wrong.
When I acid wash I titrate to establish the quantity of acid required to neutralise the soaps. That gets added to around 7% water and a pump wash carried out. After that, I've only tested the wash water with litmus paper, never done another titration.
See also Paul's replies above.
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Good news that as it means we can add the acid as needed and no worries so long as we dry it afterwards.
What he says matches what I found with the rough litmus test on the settled out 50/50 test.
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Good news that as it means we can add the acid as needed and no worries so long as we dry it afterwards.
What he says matches what I found with the rough litmus test on the settled out 50/50 test.
Just to be on the safe side, I'd do at least two or three water washes afterwards ... won't do any harm and we've proved that water washing reduces HMPEs and improves cold weather performance, unlike some commercial producers!
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Hi Julian
No problem with cut and paste my reply to the forum.
Also a quick calc that may be helpful for people using conc sulphuric acid is to X the base amount used of sodium by 0.12 for amount of acid required .
Example
2L ASM /5=400g base X ,0.12 =48ml conc sulphuric acid .
This can then be adjusted for any concentration of sulphuric acid.
Be back soon
Cheers
Paul
Tried this on a batch yesterday, correcting for 40% acid and it seems to work well. Subsequent wash water tested at pH 5. So I think I'll use this method in future, saves a lot of messing around with titration. I'll give it another couple of goes and put up up on the wiki ... thanks, Paul.
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This sounds easier and faster to use, I suppose for those of us that don't use ASM we could work backwards from a tritated sample to see if it calculates out for subsequent batches. Looking forward to the wiki.
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In the example above the 400 g is the NaOH quantity. The bit before that converts ASM to NaOH equivalent.